Frequency converters are used on board telecommunication satellites for the purpose of frequency transposition in order to transmit signals to the ground over various frequency channels dictated by the telecommunications operator.
The number of different frequency channels to be managed may be very large and their allocation when coming from the ground and their allocation on the way back to the ground may vary, and thus the number of frequency converters on board a satellite may, as a consequence, be equally large.
In addition, in order to provide service continuity in the event of equipment failure, satellite operators dictate the use of redundant equipment which further increases the total amount of equipment that it is necessary to install on board a satellite.
In the light of these constraints, there is a general problem consisting in limiting the mass, volume and overall cost of the frequency converters incorporated in a satellite payload for the purpose of carrying out frequency conversion functions associated with the number of dictated frequency channels.
Current solutions providing a required level of reliability consist in incorporating, in a satellite payload, a certain number of additional frequency converters which remain switched off (inactive) until standing in for another, failing frequency converter.
These solutions entail substantial bulk, both in terms of mass and volume, for the payload since they require the addition of a non-negligible number of additional converters. Specifically, each converter uses a specific local oscillator operating at a certain frequency. A redundant converter can only stand in for a failing converter comprising the same type of local oscillator.
The invention proposes a solution for remedying the aforementioned drawbacks which consists in a frequency converter with dual local oscillators making it possible to control multiple frequency conversion chains with one and the same local oscillator and thus make savings in terms of mass, volume and cost on the equipment installed on board the satellite.